The present invention relates to a method for controlling the print quality in an ink jet printer. The present invention also relates to an inkjet printer system which is adapted to embody the present method.
Inkjet printers comprising electro-mechanical transducers, particularly piezo-electric transducers, are sufficiently known from the prior art. In these printers, each ink duct (also referred to as ink chamber) is operationally connected to an electro-mechanical transducer. By actuating the transducer so that it deforms, a sudden volume change is achieved in the ink duct associated with this transducer. The resulting pressure wave that is produced in the duct, provided that it is strong enough, leads to a drop of ink being ejected from the nozzle of the duct. Once the pressure wave has become sufficiently small, the associated transducer may be re-actuated to eject another ink drop. By actuating the duct image-wise (or multiple ducts if the printhead comprises more than one ink duct), an image may be printed onto a receiving medium by the printhead. This image (which may be 1, 2 or 3-dimensional) is therefore built up of individual ink drops.
For it to be possible to deploy such a printer reliably, actuation settings (such as actuation frequency and amplitude and, for example, the actuation pulse form) are chosen such that they provide a predictable print quality. However, the process of searching for these actuation settings is time-consuming as it requires analyzing printed test images. From a practical point of view, this is only possible in a research or production environment. Realizing that the optimal settings may differ from printhead to printhead, and that they may change over time due to printhead use, generally useable settings are often chosen that are sub-optimal. Such sub-optimal settings provide an acceptable print quality for virtually all printheads and, furthermore, remain adequate for printing a desired image even when the printheads are changed. A disadvantage of this is that virtually no printhead is used optimally, which may lead to an intrinsically lower productivity, print quality and printhead durability.